Terminals, Consoles, Shells and Commands – Notes

🔹 Introduction

• Beginners often hear terms like command, console, and terminal.

• These might seem intimidating at first, but they’re foundational to using Linux effectively.

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🔹 Why Command Line in Linux?

• Linux is command-line oriented, though GUIs exist.

• Power users and sysadmins prefer the terminal for:

  • Efficiency

  • Flexibility

  • Control

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🔹 What is a Terminal?

• A Terminal Emulator is a program that opens a window to let you type commands.

• Common terminal emulators:

  • gnome-terminal (default on Ubuntu/CentOS)

  • konsole, xterm, guake, terminator

📌 How to Open:

• GUI: Search “terminal” in applications.

• Right-click on desktop → Open in Terminal.

• Shortcut: Ctrl + Alt + T

• Can open multiple tabs or windows.

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🔹 What is a Shell?

• A Shell is a program that interprets commands.

• Sends valid commands to the kernel for execution.

• Called the command interpreter.

📌 When it Starts:

• Automatically when a terminal is opened or user logs in via console.

📌 Features:

• Verifies syntax before execution.

• Waits for and executes commands.

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🔹 Linux is Case-Sensitive

• File names and commands must match case.

• Example: Ip, IP, and ip are all different.

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🔹 Common Shells

• Most popular: Bash

  • Default on: Ubuntu, Debian, CentOS, MacOS, WSL

• Others:

  • Bourne Shell (sh)

  • C Shell (csh)

  • Korn Shell (ksh)

  • Z Shell (zsh)

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🔹 What is a Console?

• A console is similar to a terminal but used in text-only environments.

• No GUI required.

📌 Accessing Virtual Consoles:

• Use key combos: Ctrl + Alt + F1 to F8

• One is usually used by the GUI.

⚠️ In VMs (like VirtualBox), host OS may intercept these key combos.

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🔹 Key Distinctions

💡 These terms are often used interchangeably in casual use.

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🔹 Installing & Using Terminator

• Terminator: Advanced terminal emulator with features like split views.

📌 Install:

Copysudo apt update && sudo apt install terminator

⚠️ Watch for typos – install has two Ls.

Tips:

• Add to dock for quick access.

• Use a light theme for better visibility.

• Right-click → Split Horizontally / Split Vertically for multiple terminals in one window.